610 RICHARD GOLDSCHMIDT 



very weak Japanese race, H. And the chromosomes of the latter 

 are larger. We do not, therefore, expect much information from 

 a study of the chromosomes in our case. We believe that the 

 adsorption of different c^uan titles of factor-enzymes by the chro- 

 mosome skeleton may sometimes be connected with visible dif- 

 ferences of chromosome surface; but it is not at all necessary 

 that the differences should be actually visible. 



Vlll 



If the views which, in consequence of our experiments, we feel 

 compelled to adopt, come near the truth, we should expect them 

 to be applicable to other facts in regard to sex-determination 

 (i.e., the case of Bonellia, the hormonic alteration of sex in 

 transplantation and castration experiments in birds and mam- 

 mals or in the free-martin, the case of the frog, etc.) as well 

 as to the general facts of heredity. This is actually the case 

 but we shall refrain from detailed discussion here. The appli- 

 cation is so evident that it may easily be inferred. It is, more- 

 over, by no means a new idea that factors may be regarded as 

 enzymes. Many writers have advanced similar views, as, for 

 example, Bateson, Guyer, Hagedoorn, Loeb, Moore, Woltereck 

 and the writer. And Woltereck,^ especially, has worked out the 

 idea in regard to sex-determination, in order to explain his 

 breeding results with Daphnids. He uses the view which we, as 

 well as some other Mendelian writers, also used from the be- 

 ginning of our work, that separate factors exist for both sexes. 

 These factors Woltereck calls concurring sex-substances, which 

 are present in every egg and which he conceives as zymogens. 

 One of them can become dominant either by the action of acti- 

 vators or by the action of inhibitors of the alternative zymogen. 

 Thus the zymogens are transformed into active enzymes. He 

 then works out this conception in terms of immunochemistry. 

 And since he needs definite cychcal changes of the relative valency 

 and latency for the explanation of the life-cycles, he adds the 

 necessary hypotheses for the explanation of the latter. In gen- 

 eral his hypothesis does not differ from some Mendelian formu- 

 lations which work with inhibitors; activators, changes of domi- 



